xref: /freebsd/sys/dev/uart/uart_dev_ti8250.c (revision 02e9120893770924227138ba49df1edb3896112a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2013 Ian Lepore
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "opt_platform.h"
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/conf.h>
35 #include <sys/kernel.h>
36 #include <sys/sysctl.h>
37 #include <machine/bus.h>
38 
39 #include <dev/fdt/fdt_common.h>
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 
43 #include <dev/uart/uart.h>
44 #include <dev/uart/uart_cpu.h>
45 #include <dev/uart/uart_cpu_fdt.h>
46 #include <dev/uart/uart_bus.h>
47 #include <dev/uart/uart_dev_ns8250.h>
48 
49 #include <arm/ti/ti_sysc.h>
50 
51 #include "uart_if.h"
52 
53 /*
54  * High-level UART interface.
55  */
56 struct ti8250_softc {
57 	struct ns8250_softc ns8250_base;
58 	/*uint32_t	mystuff;*/
59 };
60 
61 #define	MDR1_REG		8
62 #define	  MDR1_MODE_UART	0
63 #define	  MDR1_MODE_DISABLE	7
64 #define	SYSCC_REG		15
65 #define	  SYSCC_SOFTRESET	(1 << 1)
66 #define	SYSS_REG		16
67 #define	  SYSS_STATUS_RESETDONE	(1 << 0)
68 
69 static int
70 ti8250_bus_probe(struct uart_softc *sc)
71 {
72 	int status;
73 
74 	if ((status = ti_sysc_clock_enable(device_get_parent(sc->sc_dev))) != 0)
75 		return (status);
76 
77 	/*
78 	 * Set the hardware to disabled mode, do a full device reset, then set
79 	 * it to uart mode.  Most devices will be reset-and-disabled already,
80 	 * but you never know what a bootloader might have done.
81 	 */
82 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_DISABLE);
83 	uart_setreg(&sc->sc_bas, SYSCC_REG, SYSCC_SOFTRESET);
84 	while (uart_getreg(&sc->sc_bas, SYSS_REG) & SYSS_STATUS_RESETDONE)
85 		continue;
86 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_UART);
87 
88 	status = ns8250_bus_probe(sc);
89 	if (status == 0)
90 		device_set_desc(sc->sc_dev, "TI UART (16550 compatible)");
91 
92 	return (status);
93 }
94 
95 static kobj_method_t ti8250_methods[] = {
96 	KOBJMETHOD(uart_probe,		ti8250_bus_probe),
97 
98 	KOBJMETHOD(uart_attach,		ns8250_bus_attach),
99 	KOBJMETHOD(uart_detach,		ns8250_bus_detach),
100 	KOBJMETHOD(uart_flush,		ns8250_bus_flush),
101 	KOBJMETHOD(uart_getsig,		ns8250_bus_getsig),
102 	KOBJMETHOD(uart_ioctl,		ns8250_bus_ioctl),
103 	KOBJMETHOD(uart_ipend,		ns8250_bus_ipend),
104 	KOBJMETHOD(uart_param,		ns8250_bus_param),
105 	KOBJMETHOD(uart_receive,	ns8250_bus_receive),
106 	KOBJMETHOD(uart_setsig,		ns8250_bus_setsig),
107 	KOBJMETHOD(uart_transmit,	ns8250_bus_transmit),
108 	KOBJMETHOD_END
109 };
110 
111 static struct uart_class uart_ti8250_class = {
112 	"ti8250",
113 	ti8250_methods,
114 	sizeof(struct ti8250_softc),
115 	.uc_ops = &uart_ns8250_ops,
116 	.uc_range = 0x88,
117 	.uc_rclk = 48000000,
118 	.uc_rshift = 2
119 };
120 static struct ofw_compat_data compat_data[] = {
121 	{"ti,ns16550",		(uintptr_t)&uart_ti8250_class},
122 	{"ti,omap3-uart",	(uintptr_t)&uart_ti8250_class},
123 	{"ti,omap4-uart",	(uintptr_t)&uart_ti8250_class},
124 	{NULL,			(uintptr_t)NULL},
125 };
126 UART_FDT_CLASS_AND_DEVICE(compat_data);
127